High prevalence of active trachoma and associated factors among school-aged children in Southwest Ethiopia

Background Active trachoma is a highly contagious ongoing stage of trachoma that predominantly occurs during childhood in an endemic area. This study assessed the prevalence and factors associated with active trachoma among school-aged children. Methodology/Principal findings A community-based analytical cross-sectional study was done from March 1st to June 30th, 2021, in Southwest Ethiopia’s people’s regional state. A total of 1292 school-aged children were surveyed. The quantitative data were collected using a pre-tested, structured interview-based questionnaire and observation check list. The World health organization (WHO) simplified trachoma grading system was used to assess stages of trachoma. In this study, the prevalence of active trachoma was 570(44.1%), 95% CI (41.4, 46.9). Also, age group 6–10; being female; flies at household (HH), flies on child’s face, improved water source, improved sanitation, presence of ocular discharge, presence of nasal discharge, and unclean faces of the child were significantly associated with active trachoma. Conclusions/Significance The very high prevalence of active trachoma in the study area is significantly associated with; age group 6–10, female gender, presence of flies in household and on child’s face, presence of ocular and nasal discharge, unclean faces, improved water source, improved sanitation in the household. Thus, environmental sanitation and facial cleans trachoma elimination strategy should be intensified in the study area.


Introduction
Trachoma is a neglected tropical disease caused by the bacterium Chlamydia trachomatis [1].The disease is transmitted by direct personal contact and by flies that have come into contact with discharge from an infected person's eyes or nose [2].Trachoma limits the education and economic empowerment of infected individuals, which results in dependency and stigma [3].Communities who lack access to water, sanitation, and hygiene (WASH) were primarily affected by trachoma [4,5].
A multitude of factors were associated with active trachoma, including age of the child and the number of children [16][17][18]; as access WASH at HH [2,12,[17][18][19]; presence of ocular and nasal discharge, habit of face washing, not using soap while washing the face, and sharing towels [12,16,18].
The SAFE strategy is being implemented in endemic countries eliminate trachoma as a public health importance [20][21][22][23].But, in Ethiopia 80% of districts were endemic and majority of HH lack access to improved WASH [13,[24][25][26].However, no research has assessed the prevalence of active trachoma in the study area.This study aimed to assess the prevalence of active trachoma and associated factors among school-aged children in Southwest Ethiopia Peoples Regional State (SWEPRS).

Sample size determination and sampling technique
The sample size was calculated using Epi info software, For the first objective, with the assumptions: prevalence of active trachoma 17.5% [13], margin of error 5%, Z/2 95% CL = 1.96, and design effect 2. The calculated sample was 444.For the second objective; considering the assumption: Z/2 95% CL = 1.96, the open defecation-free status variable with OR 2.52, percent of outcome in exposed 85.5% [13], the calculated sample size was 1200 and adding 10% for non-response rate makes the final sample size 1320.
A multi-stage sampling technique was used.First, three zones: Bench-Sheko, Kaffa, and West-Omo were selected randomly.The selected zones were stratified in to rural districts and city administrations to select 12 rural districts and 4 city administrations.At least 30% kebeles in each selected strata were selected by using the lottery method.The sample was proportionally allocated to each selected kebele based on their contribution.Finally, a sampling frame was prepared by listing HH that have eligible individual, and participants were selected using a simple random sampling technique.If more than one school-aged child lived in the same HH, one child was selected by lottery method.

Variables of the study
Dependent variable.Presence or absence of active trachoma.Independent variable.Socio-demographic characteristics include: the sex of the HH head, education status of the HH head, occupation of HH the head, family size and number children aged 1 to 9 years in the HH.Behavioral factors include: frequency of face washing, using soap, discharge from the eye and nose, presence of flies on child face.
Environmental and WASH related factors includes: Prescence of feces around the HH, waste disposal, source of water, distance to water source and availability of latrine.

Operational definitions
Active trachoma: the presence of five or more follicles greater than 0.5 mm in diameter in the central part of upper tarsal conjunctiva or inflammatory thickening of the tarsal conjunctiva that obscures more than half of the normal deep tarsal vessels in either of the child's eyes [9,28].
Improved water sources: adequately protected from outside contamination, in particular from fecal matter HH connections, public standpipes, boreholes, protected dug wells, protected springs and rainwater collection [29,30].
Improved sanitation; is flush or pour-flush to piped sewer system, septic tank pit latrines, ventilated-improved pit latrines, or pit latrines with slab or composting toilets [29,30].
Unclean face: Any dust and food on the face during clinical examination [16].

Data collection methods and materials
The data were collected using a structured interviewer-administered questionnaire, and observational checklist prepared and adopted after reviewing relevant literature [16,18], and a simplified WHO trachoma grading system [9,28].The interview questionnaire measures sociodemographic characteristics, and behavioral factors.The interview was conducted by four trained public health professionals in the participants compound where they are comfortable.The observation check list was used to measure the HH and surrounding for WASH status.The observation was done by four trained environmental health professionals immediately after the interview was completed.The clinical trachoma grading was done by four trained BSc nurses to clinically diagnose each eye of the child.

Socio-demographic characteristics of the study participants
In this study 1292 school-aged children participated; the response rate was 97.87%.Nearly half of the study participants were female (55%) and in the age group 6-10 (53%).The majority of study participants (86%) were rural.Moreover, 46% and 12% of the study participants were from 1 st cycle and 2 nd cycle primary schools, respectively.Also, 42% of the participants did not enroll in school (Table 1).

Environmental characteristics of the households and surrounding
In this study, (55%) and (56%) of the HH have improved water sources and sanitation.Only 17% of the HH get water within premises.The latrine coverage was 572(44%), but 729(56%) of the child defecate in the field.In 819(63%) and 468 (36%) of the compound of the HH and around the HH human feces and animal feces were observed respectively.In 503(39%) of the HH domestic animal were present.In 956(74%) of the HH the waste disposal system was improper, and in 567 (44%) of the HH flies were observed (Table 2).

Behavioral characteristics of the school aged children
In this study only 374(29%) of school aged children wash their hands and face daily.But only 6% of them uses soap to wash their hands and face.Also, nasal and ocular discharge were observed in 203 (16%) and 220 (17%) of school aged children respectively.Half 646 (50%) of school aged children participated in the study lack facial cleans (Table 3).

Prevalence of active trachoma
In this study, the overall prevalence of active trachoma among school aged children in was 44.12 with 95% CI (41.4,46.9) (Fig 1).

Factor associated with active trachoma
In bivariable logistic regression age group, gender, number of children aged 1-9 years, water source, face washing, availability of latrine, sanitation, human and animal feces at HH, flies in the HH, ocular and nasal discharge, flies on the child's face, and condition of child's face were variables showed association at p value less than 0.2.In the multiple logistic regression, age group, gender, water source, sanitation status, flies at HH, ocular discharge, nasal discharge, flies on the child's face, and condition of child's face were the variables significantly associated with active trachoma at P value less than 0.05.Accordingly, the odds of active trachoma were 2.15 times higher among study participants in the age group 6-10 years than those in the age group 11-16 year [adjusted OR = 2.15 (95% CI: 1.51-3.06)].Similarly, the odds of active trachoma were 15.36 times higher among female children than males [adjusted OR = 15.36 (95% CI: 10.79, 21.86)].Also, the odds of active trachoma were decreased by 53% and 31% among study participants who have access to improved water source and improved sanitation at their HH [adjusted OR = .47(95% CI: (.33,.67)]and [adjusted OR = .31(95% CI: (.22,.59)] respectively.
In addition, the odds of trachoma were 16.26 and 7.19 times higher among study participant in whom HH flies were observed at their HH and on their face [adjusted OR = 16.26 (95% CI: (9.93,26.64)]and [adjusted OR = 7.19 (95% CI: (3.87,13.34)]respectively.On top of this, the odds of active trachoma were 10.18 and 1.61 times higher among study participants Moreover, the odds of active trachoma were 2.29 times higher among study participants whose faces were unclean [adjusted OR = 2.29 (95% CI: 1.57, 3.34)] (Table 4).

PLOS NEGLECTED TROPICAL DISEASES
had been carried out prior to the COVID-19 pandemic; yet, the pandemic had impeded the progress of the 2020 trachoma elimination goal [38].
In this study, the odds of active trachoma were 2.15 times higher among children in the age group 6-10 year as compared to those in the age group 11-16 year.This result is in line with finding from similar research [37,39].Its due to the fact that younger children do not follow hygiene practice to protect them self from trachoma [2,39,40].
Also, the odds of active trachoma were 15.36 times higher among female school-aged children than male.The finding is supported by similar research findings and other evidence [13,39,41].The gender disparity in acquiring active trachoma among girls can be associated with the gender role that baby girls play in taking care of younger family members who are potential sources of trachoma infection.This disproportionate risk can persist even in the later age of the girl as a woman because of the raising of children, which increases the recurrent acquisition of the infection, complications, and blindness.
In addition, the odds of active trachoma decreased by 53% and 69% among school-aged children who have access to improved water sources and improved sanitation in their HH.This is in line with the study findings, because lack of access to improved WASH facilities in HH is a barrier to maintain personal and environmental hygiene [16,33,36].Majority of HH in Ethiopia lacks access to improved WASH, children living in this HH are at increased risk of trachoma [26].
Subsequently, the odds of active trachoma were 16.26 and 7.19 times higher among participants in whom HH and face flies were observed, respectively.The finding was in line with results from similar studies because certain species of flies act as mechanical vectors for trachoma infection by transporting the bacteria from infected children to healthy children [2,16,21,37,42].
Moreover, the odds of active trachoma were 10.18, 1.61, and 2 times higher among schoolaged children on whom ocular and nasal discharge were observed and whose faces conditions were unclean, respectively.The result is in line with findings from similar studies [12,13,16,19,33].This is because an unclean face, nasal discharge, and ocular discharge attract flies, which transmit the bacteria from infected children to healthy children [2].

Strengths and limitations of the study
The limitation of this study was cross-sectional nature of the design, which is difficult to show temporal relation between variables.Social desirability bias was also potential limitation, but using observation check list had minimized it.Moreover, addressing most trachoma impacted population, with relatively large sample size and large geographical coverage is the strength of the study.

Conclusion
This study found that the prevalence of active trachoma among school-aged children was very high when compared with the WHO threshold.Also, age group 6-10, female gender, presence of ocular and nasal discharge, unclean face of the child's, presence of flies on the child's face, and at HH have significantly associated with increased odds of active trachoma among schoolaged children, while access to improved water sources and improved sanitation lowered the odds of active trachoma among school-aged children.Thus, to reduce the high prevalence of active trachoma in the study area, intensifying and scaling up the facial cleanness and environmental and sanitation components of the SAFE strategy is needed by giving great attention to those in the age group 6-10 and female gender.